The effect of procedural end-tidal CO2 on infarct expansion during anterior circulation thrombectomy

BACKGROUND

Carbon dioxide is a potent cerebral vasodilator that may influence outcomes after ischemic stroke. The objective of this study was to investigate the effect of intraprocedural mean end-tidal CO2 (ETCO2) levels on core infarct expansion and neurologic outcome following thrombectomy for anterior circulation ischemic stroke.

METHODS

A retrospective review was conducted of consecutive patients from March 2020 to June 2021 who underwent mechanical thrombectomy for acute anterior circulation ischemic stroke under general anesthesia and achieved successful recanalization (Thrombolysis in Cerebral Infarction [TICI] ≥ 2b). Only patients with CT perfusion, procedural ETCO2, and postoperative MRI data were included. Segmentation software was used for multi-parametric image analysis. Normocarbia defined as mean ETCO2 of 35 mmHg was used to dichotomize subjects. Univariate and multivariate statistics were applied.

RESULTS

Fifty-eight patients met criteria for analysis. Of these, 44 had TICI 3 recanalization, 9 had TICI 2c, and 5 had TICI 2b. Within this combined recanalization group, patients with mean ETCO2 > 35 had significantly higher rates of functional independence at 90 days. Although patients tended to salvage more penumbra and experience smaller final infarcts when ETCO2 exceeded 35 mmHg, this did not reach statistical significance.

CONCLUSIONS

Stroke patients who underwent successful thrombectomy with general anesthesia achieved higher rates of functional independence when procedural ETCO2 exceeded 35 mmHg. Further studies to confirm this effect and investigate optimal ETCO2 parameters should be considered.

Rapid Evolution and Rupture of an Incidental Aneurysm During Hyperdynamic Therapy for Cerebral Vasospasm

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is associated with high morbidity and mortality. Among the most common sequelae of aSAH is delayed cerebral ischemia. Hyperdynamic therapy (fluid supplementation and hypertension) is used to increase cerebral perfusion. However, the safety of hyperdynamic therapy in patients with separate unruptured, unsecured intracranial aneurysms is not well-established. Herein, a rare case demonstrating the rapid evolution and rupture of an incidental unsecured aneurysm in the setting of hyperdynamic therapy is presented.

CASE DESCRIPTION

A 56-year-old woman without significant medical history presented with aSAH secondary to rupture of a 3-mm left posterior inferior cerebellar artery aneurysm. After endovascular treatment of this aneurysm, she developed symptomatic vasospasm prompting initiation of hyperdynamic therapy. Seven days after initiation of hyperdynamic therapy, she experienced rupture of an incidental pericallosal artery aneurysm that was found to have increased in size during the hyperdynamic therapy. She ultimately survived and was functionally independent approximately 1 year after her initial ictus.

CONCLUSIONS

This case demonstrates that enlargement and rupture of an incidental, previously unruptured aneurysm may occur during hyperdynamic therapy.

Cerebellar Arteriovenous Malformation Rupture Despite Apparent Angiographic Obliteration

BACKGROUND

Arteriovenous malformations (AVMs) can occur in all regions of the brain and spinal cord, with clinical consequences and risks varying by location. Delayed AVM rupture despite digital subtraction angiography-confirmed obliteration post-radiation is exceedingly rare.

CASE DESCRIPTION

To our knowledge, we present the first documented case of delayed hemorrhage associated with a cerebellar AVM 5 years after linear accelerator-based radiation in a man aged 31 years despite apparent angiographic obliteration.

CONCLUSIONS

Intracranial hemorrhage after radiosurgery in digital subtraction angiography-confirmed obliterated AVMs is rare, with limited understanding of risk factors, appropriate preventative management, and mechanisms of occurrence. This case serves to demonstrate the need for greater awareness of this rare complication, as well as the need for appropriate surveillance and management strategies.